Kaskaskia, Illinois

Kaskaskia is a village in Randolph County, Illinois on the Mississippi River. Having been inhabited by indigenous peoples, the village was settled by France as part of the Illinois Country and was named for the Kaskaskia people. Its population peaked around 7,000 as a regional center in the 18th century. During the American Revolutionary War, the town, which had become an administrative center for the British Province of Quebec, was taken by the Virginia militia during the Illinois campaign. It was briefly designated as the county seat of Illinois County, Virginia, after which it became part of the Northwest Territory under the United States government in 1787. Kaskaskia was also named as the capital of the United States' Illinois Territory, created on February 3, 1809. In 1818, when Illinois became the 21st U.S. state, the town served as the state's first capital until 1819, when the capital was moved to more centrally located Vandalia.

Most of the town was destroyed by flooding in April 1881 when the Mississippi River shifted eastward to a new channel, taking over the lower 10 mi (16 km) of the Kaskaskia River. This resulted from deforestation of the river banks during the 19th century, due to crews taking wood for fuel to feed the steamboat and railroad traffic. The river then passed east rather than west of the town. The state boundary line, however, remained in its original location. A small bridge crosses the old riverbed, which became a creek that sometimes fills with water during flood season.

In the 2020 United States census the population was 21, making it the third-least populous incorporated community in Illinois behind Valley City (pop. 14) and Florence (pop. 17). Kaskaskia has an Illinois telephone area code (618) and a Missouri ZIP Code (63673). Its roads are maintained by Illinois Department of Transportation, and its few residents vote in Illinois elections. The town was evacuated in the Great Flood of 1993, which covered it with water more than 9 ft (3 m) deep.